The authors evaluate the work process and its effect on workers' health in a cement factory in the State of Rio de Janeiro. The interactive methodology consisted of different approaches to assessing the workplace through the incorporation of various institutions working in the field of Workers' Health, professionals from different backgrounds, and the trade union, valorizing the workers' experience and actively contributing to the surveillance process under the Unified National Health System (SUS). Levels of particulate matter and noise were measured. The mean level of free crystalline silica in the particulate matter was 2%, resulting in a tolerance limit as specified under Brazilian legislation (NR-15), or 2.0mg/m³. The concentration of particles both in samples collected in the workers' respiratory zone and in area samples varied from 3.59 to 52.44mg/m³. Noise varied from 83dB to 110dB. The majority of the values were higher than the maximum limits set by Brazilian legislation. These results, together with the opinions expressed by the workers themselves, showed an unhealthy workplace and work process, placing the workers' health at risk.